coyote: CGMAP_CONTINENTS

Description
Provides a simple wrapper to the MAP_CONTINENTS command in IDL that can be used
to draw map continental outlines in a device and color independent way with 
Coyote Graphics programs.
Categories
Graphics, Map Projections
Examples
To display a map of Cuba and Haiti::
    cgMap_Set, /Mercator, Limit=[5.0, -95, 35.0, -55.0]
    cgMap_Continents, Background='dodger blue', /Continents, /Fill, Color='tan'
    cgMap_Continents, /Countries, /USA, Color='navy', /Continents
Keywords
addcmd: in, optional, type=boolean, default=0
   If this keyword is set, the object is added to the resizeable graphics
   window, cgWindow. Note that a map projection command must be 
   added to the window before this command is added to be effective.
background: in, optional, type=string
   The name of the background color. A polygon of this color is drawn
   in the map space set up by the map projection before continents and
   other items are drawn.
coasts: in, optional, type=boolean, default=0
   Set this keyword if you want coasts to be drawn. This keyword is ignored if using FILENAME.
color: in, optional, type=string, default='opposite'
   The name of the drawing color for the program.
continents: in, optional, type=boolean  
   Set this keyword if you want continental outlines to be drawn. This will be
   set automatically if COASTS, COUNTRIES, RIVERS, and USA keywords are all set
   to zero. This keyword is ignored if using FILENAME.
countries: in, optional, type=boolean, default=0
   Set this keyword to draw political boundaries.
fill_continents: in, optional, type=boolean, default=0
   Set this keyword to draw filled polygons rather than outlines. If the value is
   2, the continents are filled with lines rather than colors.
hires: in, optional, type=boolean, default=0
   Set this keyword to use the high-resolution data supplied with IDL for MAP_CONTINENTS.
   This keyword is ignored if using FILENAME.
limits: in, optional, type=fltarr(4)
   Set to a four-element vector, [Latmin, LonMin, LatMax, LonMax] that describes the 
   limit rectangle. Only plot line segments that pass through this rectangle.
linestyle:  in, optional, type=integer, default=0
   Set to the type of linestyle in drawing outlines. Set solid lines by default.
map_structure: in, optional, type=struct/object
   Set this keyword to a map structure as returned by Map_Proj_Init or to a map
   coordinate object (i.e., cgMap) from which a map structure can be obtained.
mlinestyle:
   This keyword depreciated in favor of LINESTYLE keyword.
mlinethick:
   This keyword depreciated in favor of THICK keyword.
orientation: in, optional, type=float, default=0.0
   Set this keyword to the counterclockwise angle in degrees from horizontal that 
   the line fill should be drawn. Only applies if the FILL_CONTINENTS keyword is 2.
outline: in, optional, type=boolean, default=1
   Draw outlines of coastlines (really just sets the `COASTS` keyword). The `COASTS`
   keyword overrides this setting.
rivers: in, optional, type=boolean, default=0  
   Set this keyword if you wish to draw rivers. This keyword is ignored if using FILENAME.
spacing: in, optional, type=float, default=0.5
   Set this keyword to the spacing, in centimeters, for a line fill. This keyword only has 
   effect if the FILL_CONTINENTS keyword is set to 2.
t3d: in, optional, type=boolean, default=0  
   Set this graphics keyword if you wish to draw outlines use the T3D transformation matrix.
   This keyword is ignored if using FILENAME.
thick: in, optional, type=integer, default=!P.Thick
   Set this keyword to the thickness of the lines that are drawn.
usa: in, optional, type=boolean, default=0  
   Set this keyword if you wish do draw United States state boundaries. This keyword is 
   ignored if using FILENAME.
zvalue: in, optional, type=float, default=0.0  
   Set this keyword to the ZVALUE where the outlines should be drawn. Set to 0 by default.
   This keyword is ignored if using FILENAME.
Author
FANNING SOFTWARE CONSULTING::
   David W. Fanning 
   1645 Sheely Drive 
   Fort Collins, CO 80526 USA 
   Phone: 970-221-0438 
   E-mail: david@idlcoyote.com 
   Coyote's Guide to IDL Programming: http://www.idlcoyote.com
History
Change History::
   Written by David W. Fanning, 7 November 2011.
   Added an ERASE=0 to the /NOGRAPHICS keyword on the Draw method call to cgMap. 27 Dec 2011. DWF
   Changed the default line thickness to !P.Thick to better support PostScript files. 28 Dec 2011. DWF.
   Modified slightly to allow a three-element byte array to be used as the COLOR. 18 April 2012. DWF.
   Added a BACKGROUND keyword. 31 Aug 2012. DWF.
   Implemented the OUTLINE keyword and make it default so outlines are drawn when, e.g., FILL_CONTINENTS=2. 23 Nov 2015. Joe Sapp.
Copyright
Copyright (c) 2011-2012, Fanning Software Consulting, Inc.